by Houda Bekkari , PhD; Dr. Yousra Benmakhlouf, PhD; Prof. Naima Ghailani Nourouti, PhD; Prof. Amina Barakat, PhD; and Prof. Mohcine Bennani Mechita, PhD

All authors are with Intelligent Automation and BioMed Genomics Laboratory, Faculty of Sciences and Techniques of Tangier, at Abdelmalek Essaadi University, Morocco in Tangier, Morocco.

Funding: No funding was provided for this article.

Disclosures: The authors have no conflicts of interest relevant to the content of this article.

Innov Clin Neurosci. 2024;21(7–9):10–14.

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Abstract

Objective: Intellectual disability (ID) is considered one of the most common human disorders characterized by significant deficits in cognition and functional and adaptive skills. The aims of this study were to describe the demographic and clinical features of a group of Moroccan individuals with ID living in the Tangier-Tetouan region.

Design: This was a retro-prospective and descriptive exploratory monocentric study realized between November 2020 and August 2023. A total of 109 patients with ID were included. They were selected at four mental health centers in the Tangier-Tetouan region. Our data were treated and analyzed using the IBM SPSS version 26.

Results: A male predominance of patients with ID was observed in our series (54.4% male vs. 42.6% female). The male-to-female ratio was 1.34. The mean±standard deviation (SD) age of our patients was 11.75±4.87 years, ranging from 1 to 35 years. The mean ages of mothers and fathers at the births of their children with ID were 28.36 and 35.6 years, respectively. Many co-occurring medical conditions were noted in our data (speech delay: 20.5%, concentration problems: 15.1%, hyperactivity: 11.1%, ambulation difficulties: 8.8%, aggressiveness: 8%, vision problems: 6.3%, epileptic seizures: 4%). The consanguinity rate was 26.9 percent.

Conclusion: ID associated with genetic causes was significantly correlated with the consanguinity rate in the Moroccan population.

Keywords: Intellectual disability, clinical characteristics, Morocco, consanguinity, demographic characteristics, genetic causes

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At present, there is an increased worldwide prevalence of mental disorders. They are characterized by clinically significant perturbation in an individual’s emotional regulation, cognition, or behavior.¹ Intellectual disability (ID) is a neurodevelopmental disorder that manifests before the age of 18 years; it has been defined by significant cognitive deficits, which have been established through a standardized measure of intelligence, in particular with an intelligence quotient (IQ) score below 70, and also by significant deficits in functional and adaptive skills.² According to the World Health Organization (WHO),³ ID is grouped into five forms based on IQ scores: profound, severe, moderate, mild, and borderline intellectual functioning. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) retains this classification with more focus on diagnostic criteria and the levels of support needed to achieve an individual’s optimal personal functioning.⁴ As reported by the DSM-5-TR, individuals with profound ID (IQ<20) require 24-hour care due to significant developmental delays in all areas and noticeable physical and congenital abnormalities. Individuals with severe ID (IQ 20–34) develop receptive language skills better than expressive language skills, and they might communicate in a variety of ways, such as sign language, written communication, and use of technology. They might have significant developmental delays in communication. They require daily assistance with self-care activities and safety supervision. For moderate ID (IQ 35–49), independent living can be achieved with moderate levels of support. These individuals have noticeable developmental delays in speech and motor skills, but they can communicate in simple ways. Individuals with mild ID (IQ 50–70) experience slower development than is typical in all developmental areas. However, they can learn practical life skills and live independently with minimum levels of support. Individuals with borderline ID (IQ 70–80) are able to lead independent lives if they receive extra support. In the worldwide population, it has been reported that 75 to 90 percent of the affected individuals have mild ID.⁵

As reported by the American Association of Intellectual and Developmental Disabilities, ID is the most common developmental delay, with a prevalence of about three percent in the global population.⁶ It tends to be more prevalent in developing countries.⁵ It is 1.3 times more frequent in male individuals than female individuals.⁷

While the sources of ID are heterogeneous, its etiopathogenesis is mainly classified into environmental exposure and genetic abnormalities.⁷ One study noted genetic abnormalities in about 40 percent of all ID cases.⁸ Based on its etiology, ID can also be divided into syndromic ID, which includes individuals with one or more clinical features and behavioral signs in addition to ID, and non-syndromic ID, wherein ID is the sole clinical feature.⁹

As far as we know, very few studies have focused on ID in Morocco. This present study is a continuity of the first and only prospective study concerning ID in Morocco, especially in Fes City, published by our team in 2020.¹⁰ Therefore, this work aimed to describe the demographic and clinical characteristics of Moroccan patients with ID living in the Tangier-Tetouan region.

Subjects and Methods

This descriptive, retro-prospective study was carried out between November 2020 and August 2023. Patients with ID were selected at four mental health centers in the Tangier-Tetouan region: Enfants du Paradis and Assadaka Association in Tangier and Hanane and Basmat Amal Association in Tetouan. In total, 109 subjects were included. Patients with syndromic and non-syndromic ID were eligible for inclusion. The average patient age was 11.75 years. All patients’ IQs were lower than 70. Patients with only hearing disabilities were excluded from our cohort.

This study protocol was approved by the Hospital-University Ethics Committee in Tangier City (CEHUT), Morroco. All procedures were in compliance with their ethical standards. Written informed consent was received from the tutors of all participants.

Statistical analysis. We analyzed our data with the IBM SPSS version 26, which provides improved survey analysis. Our results were expressed as percentages. Our research considered a two-sided p-value less than 0.05 (the significance level) statistically significant.

Results

Demographic information. In the present study, 109 patients were included (68 with non-syndromic ID and 41 with syndromic ID) and recruited from the Tangier-Tetouan region, a region of Morocco with overall similar socioeconomic conditions and lifestyles. The percentage of male participants was higher than female participants in our sample (57.4% vs. 42.6%). The male-to-female ratio was 1.34. The sample was young, consisting of patients aged between 1 and 35 years. The mean±standard deviation (SD) age of our patients was 11.75±4.87 years, with almost all patients aged between 5 to 15 years (79.6% were between 5–15 years, 13.9% were between 26–35 years; Table 1).

The most commonly known risk factors responsible for ID are divided into genetic causes (e.g., heredity, syndromes), environmental factors (e.g., complications during pregnancy, prematurity, birth asphyxia, infections, accidents, and trauma), or unexplained. According to our results, 42.3 percent of patients had ID with a genetic background, of which 26.4 percent had a familial form of ID. A total of 30.7 percent of our patients had ID with environmental factors; 5.7 percent were prenatal (infection 3.8% and complication during pregnancy 1.9%) and 25 percent were perinatal (asphyxia 19.2 and prematurity 5.8%; Table 2).

The fathers’ ages at the births of their children with ID ranged between 18 and 60 years. The mean age was 35.6 years. Over 63 percent of children were born to young mothers between the ages of 18 and 30 years. The mean age was 28.36 years.

Considering parents’ education levels, more than 32 percent of parents were illiterate, 23 percent had a basic level of education (primary school), and more than half of parents had had an educational level between primary and second level. Only 8.9 percent had a post-secondary level of education (university).

The majority of mothers were housewives (86.9%), while 6.5 percent were unskilled workers, 5.6 percent were salaried workers, and 0.9 percent were merchants. Regarding the fathers, more than half were unskilled workers, 23.2 percent were merchants, and 12.6 percent were salaried workers.

Clinical characteristics. In our study, all participants at the four mental health centers had mild ID (IQ 50–70). These receiving centers evaluated the IQ of patients in two ways, either using the Weschler intelligence scale test or their own questionnaire.

The evaluation of the adaptive skills of our patients in the five domains of the Vineland Adaptative Behavior Scale (communication, daily living skills, socialization, motor skills, and maladaptive behavior) have been established using a parent questionnaire. Common co-occurring medical conditions included delayed language learning, concentration problems, hyperactivity and agitation, ambulation difficulties, aggressiveness, and vision problems. Delayed speech (20.5%) and concentration problems (15.1%) were the most common symptoms. Other abnormal behaviors that were detected in 4 to 5 percent of patients included memory problems, eating disorders, sleep disorders, and epileptic seizures. A center specialist assessed these symptoms after interviewing parents, who provided a medical and family history of psychiatric problems (Table 3).

Treatment. The majority of the population studied (79.8%) did not take any medications; 13.5 percent of them took antiepileptic drugs to treat epileptic seizures, 2.9 percent took anxiolytic drugs, 1.0 percent took supplements for concentration, and 2.9 percent took medications for other diseases (e.g., heart disease, anemia).

The four mental health centers we collaborated with provided physiotherapy and speech therapy to their patients. A total of 31.4 percent of patients worked with a speech therapist, 15.7 percent with a physiotherapist, and 26.5 percent participated in both speech therapy and physiotherapy.

Discussion

Although ID is potentially the largest impairment grouping in several countries worldwide, including those in Africa, few indigenous research studies have been undertaken. To our knowledge, this is the second retro-prospective study conducted in Morocco and the first in the north of Morocco, which aimed to describe the demographic and clinical characteristics of ID in a series of Moroccan individuals to enrich the literature of ID in this country. Thus, we identified 109 urban and rural patients who shared similar socioeconomic conditions and lifestyles and had attended one of four mental health centers in the Tangier-Tetouan region: Enfants du Paradis or Assadaka Association in Tangier or Hanane or Basmat Amal Association in Tetouan.

In our series, a male predominance was revealed (57.4% vs. 42.6%) with a male-to-female sex ratio of 1.34; this was in agreement with a study by Karam et al¹¹ (52% vs. 48%) and in accordance with several studies that have consistently shown that affected male individuals outnumber female individuals by about 30 percent.^12–14 The biological inequity between male and female individuals conferred by the presence of a single X chromosome in male individuals has been considered to be primarily responsible for such a significant sexual bias, suggesting a primary role for genes on the X chromosome in the causation of ID, with the fact that nearly 40 percent of X chromosomes genes are expressed in brain.¹⁵ However, this genetic imbalance is partially compensated for by the random inactivation of one of the two X chromosomes in female cells.¹⁶ As a result, any alteration in an X-linked gene will fully express itself in a male individual, whereas X-inactivation will mitigate the effect in female individuals.¹⁷ In Morocco, the ratio of attendance at primary school is different for male and female children, especially in rural areas (26% of girls vs. 79% of boys);¹⁸ female children do not have the same educational opportunities in the Moroccan educational system, as some parents give preference to their sons over their daughters, and this might reflect the fact that more cases of ID among female children could be diagnosed if they attended primary school.

Another contributing factor is that male youths exhibiting mental health symptoms are likelier to be diagnosed as patients with ID than female youths. Boys who are underperforming in school might tend to call attention to themselves and be labelled as having “behavioral problems,” whereas girls having difficulties might tend to sit quietly in the back of the class and thus be overlooked. Since many teachers prefer quiet children to disruptive children, boys are likelier to be referred to the school psychologist for testing or sent to the principal for discipline. It does not mean there are more boys with ID than girls—it simply means that a poorly functioning boy is more likely to come to the attention of school or medical authorities.¹⁹

Analysis of our data showed that more than half (53.4%) of the patients in our sample were underdiagnosed in their early years as patients with ID. They were not recognized until they reached the age of education, when their academic underperformance became evident. They had been enrolled at mental health centers after the age of seven years (the legal age of education in Morocco) to improve their communication skills and benefit from education. A total of 46.3 percent of our patients visited the center before seven years of age, of whom 17.1 percent were individuals with trisomy who were diagnosed with syndromic ID from birth. Hence, their parents enrolled them from an early age directly at a mental health center. In Morocco, neither medical coverage nor public specialized institutions are guaranteed to be available for patients with ID; only some educational associations are partially supported by the state, whereas others are not supported by the state at all. Most of these associations were created by parents who could not find any support structure for their children with ID. However, support is still insufficient.

While many causes of ID are unknown, its etiology is mainly divided into genetic abnormalities and environmental exposure.²⁰ According to our results, 30.7 percent of ID causes were environmental (e.g., complications during pregnancy, prematurity, birth asphyxia, or infections) during the prenatal or perinatal stage. A total of 19.2 percent of patients had birth asphyxia; they were born with blue skin and did not cry immediately after birth because their brain and other organs did not get enough oxygen during or after birth. Many studies have revealed the negative effect of prenatal stress exposure on the fetus’s brain development,²¹ reflected in the children’s lower general intellectual and language abilities.²² Autism spectrum disorders in children have also been associated with stress exposure in pregnant women, especially in late pregnancy.²³ Regarding our results, more than 10 percent of the mothers had been exposed to high levels of stress and anxiety in different stages of their pregnancy for various reasons (e.g., unplanned pregnancy, relationship difficulties, depression, spousal abandonment, expecting and apprehensions related to having a baby with ID). This stress potentially led to the increase of the placental cortisol,²⁴ which plays a role in the cognitive development of children.²⁵

Poor women in Morocco, especially in rural areas, remain the least likely to have adequate healthcare during pregnancy and childbirth. They might not be able to do all the necessary prenatal tests, especially the first trimester tests, and they often do not have supervised births (61% in rural areas vs. 38% in urban areas).²⁶ This might be due to poverty, lack of awareness, and urban transport challenges. Mental disability is the third deficiency encountered among people with disabilities in Morocco (22.69%).²⁶

Genetic causes are the most common reasons for ID or delayed psychomotor development.²⁷ They were noted in many of our patients (44%). This rate was in accordance with the literature data (25–50%).²⁸ Numerous studies in various countries have indicated that consanguineous marriages, particularly between first-degree cousins, increase the risk of various hereditary disorders, including ID and other psychiatric disorders.²⁹ Our findings showed that 26.9 percent of this patient group were the offspring of biologically related parents. There was a significant relationship between consanguinity and ID associated with genetic causes (p=0.017). The Moroccan population has practiced interfamily marriages for generations as a part of the cultural tradition. Thus, Morocco is considered one of the countries with a high rate of consanguinity (15.25%). However, it remains at a lower rate than its North African and Arab neighbors (22–25% in Algeria, 29% in Egypt, 25% in Lebanon, 51.3% in Saudi Arabia, and higher in Tunisia).³⁰

In our series, more than 63 percent of children were born to mothers aged 20 to 29 years, while 45.3 percent were born to fathers under the age of 40 years. The average age at first marriage in the Moroccan population is 25.5 years for women compared to 31.9 years for men.³¹ Parental age can affect children’s cognitive development through many possible pathways.³² Older mothers are typically more likely to have children with ID, partially due to increased risk for lower birth weight.³³ The incidence of autism spectrum disorders is elevated when children are born to older biological mothers³⁴ or fathers;³⁵ recent studies suggested that the increased de novo mutations in men’s sperm as they age can contribute to neurodevelopmental disorders.^36,37 On the other hand, previous research showed that the offspring of mothers aged 12 to 19 years had a 51-percent increased risk of having a mental disorder.³⁶ The number of marriages of minors in our country is increasing, rising from 12,600 in 2020 to 19,369 in 2021.³¹ Contrary to some studies that approved that daily exposure of parents to ionizing and chemical products (e.g., plumb, mercury, and pesticides) at work during pregnancy affects fetal development,³⁸ none of parents in this study had this type of function.

Delayed language development was the most common symptom in this sample (20.5%). This was in accordance with literature data that considered speech delay a common sign in individuals with moderate ID.³⁹ Epilepsy is often associated with ID as a comorbidity. However, in certain circumstances, ID is considered a consequence of epilepsy⁴⁰ since some factors can increase the risk of a drop in IQ score, such as the severity of epileptic seizures, frequency, and onset early in childhood.⁴¹ However, epileptic seizures were observed only in four percent of our patients. People with ID might have a low and narrow ability to concentrate,⁴² which was observed in eight percent of this sample as a common clinical symptom.

The treatment of ID is symptomatic and not curative; patients can benefit from psychopharmacological and psychological treatment, such as behavior therapy.⁴³ As mentioned above, 2.9 percent of our patients took anxiolytic medications for anxiety symptoms, and 13.5 percent took antiepileptic drugs to treat and prevent seizures, which could cause many unwanted side effects for patients.⁴⁰

Recently, some studies have shown the positive effect of an energy healing system, known as the yoga prana vidya system (YPV), on children with ID; it is an energy body healing system that utilizes no drugs and no touch protocols.^44,45 A pilot study that applied YPV on children with ID revealed a significant increase in concept tests, concentration, understanding, memory tests, social behavior, some increase in IQ and drawing tests, and a reduction in frequency, duration, and severity of seizures in subjects with epilepsy.⁴⁴ Other research suggested that yoga healing would be an attractive therapeutic option for epilepsy, as it might influence the electroencephalogram and the autonomic nervous system, thereby controlling epileptic seizures.⁴⁶ It might also enhance cognition and greater gray matter volume in various brain areas.⁴⁷ Based on our information, energy healing, in general, has started to be integrated into very few centers in Morocco.

Limitations. This study was not without limitations. Many factors influenced the sample size. Illiteracy and lack of awareness of ID in the Moroccan population limits access to ID centers. Some parents explain the symptoms of ID via myths, so they might keep their children at home without any medical examinations or shy away from exposing them to society. In addition, poverty and not providing free medical coverage to these patients makes their diagnoses difficult and incomplete. Furthermore, the lack of ID centers in Morocco and the rejection from some to contribute to and participate in such research also contributed to the limited size of our sample. Future research with more samples of patients with ID from other mental health centers are recommended to validate and confirm our preliminary findings.

Conclusion

The present study highlighted some demographic and clinical features of ID in Morocco. Our data suggested that ID was, in part, due to the prevalence of consanguineous marriages, since a significant correlation between ID associated with genetic factors and the consanguinity rate (p<0.05) was found in our research; hence, there is a need to set up a program of mass health education and genetic counseling in Morocco. These findings are consistent with those of our previous study in Fes City. This work could enrich the literature on ID in Morocco by providing data for comparison to other researchers.

The lack of awareness of ID and its risk factors, poverty, and a lack of medical coverage provided to individuals with ID to allow for free diagnoses and treatment constitute a real challenge in Morocco.

Acknowledgments

We are very grateful to all participants and our association’s collaborators for subject recruitment: Enfants du Paradis and Assadaka Association in Tangier and Hanane and Basmat Amal Association in Tetouan.

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